We have developed a photochemical method for the site-selective deposition of semiconductor quantum dots onto nanocrystalline TiO₂ films. The quantum dots are adsorbed to TiO₂ surfaces through bifunctional mercaptoalkanoic acid (MAA) linkers. The optical densities of the films are tunable by varying the quantum dot surface coverage. Site-selective adsorption of quantum dots is achieved by the TiO₂-catalyzed photooxidative degradation of surface-adsorbed MAAs. The quantum dot adsorption is decreased or completely ‘turned off' in illuminated regions of the film. Micropatterned films have been produced by illumination through a photomask, and have been characterized by scanning electron microscopy and energy dispersive X-ray analysis. This presentation will focus on the self-assembly and photopatterning mechanisms. In addition, the potential applications of the technique in the solution-phase fabrication of nanostructured materials will be discussed.